The rise of the information society offers not only considerable peril but also great promise. Beset from all sides by a never-ending barrage of media, how can we ensure that the most accurate information emerges and is heeded?

In this book, Cass R. Sunstein develops a deeply optimistic understanding of the human potential to pool information, and to use that knowledge to improve our lives. In an age of information overload, it is easy to fall back on our own prejudices and insulate ourselves with comforting opinions that reaffirm our core beliefs. Crowds quickly become mobs. The justification for the Iraq war, the collapse of Enron, the explosion of the space shuttle Columbia — all of these resulted from decisions made by leaders and groups trapped in information cocoons, shielded from information at odds with their preconceptions. How can leaders and ordinary people challenge insular decisionmaking and gain access to the sum of human knowledge?

Stunning new ways to share and aggregate information, many Internet-based, are helping companies, schools, governments, and individuals not only to acquire, but also to create, ever-growing bodies of accurate knowledge. Through a ceaseless flurry of self-correcting exchanges, wikis, covering everything from politics and business plans to sports and science fiction subcultures, amass — and refine — information. Open-source software enables large numbers of people to participate in technological development. Prediction markets aggregate information in a way that allows companies, ranging from computer manufacturers to Hollywood studios, to make better decisions about product launches and office openings. Sunstein shows how people canassimilate aggregated information without succumbing to the dangers of the herd mentality — and when and why the new aggregation techniques are so astoundingly accurate.

In a world where opinion and anecdote increasingly compete on equal footing with hard evidence, the on-line effort of many minds coming together might well provide the best path to infotopia.

"This extraordinary work synthesizes the latest in how we know, with the latest in what the web has become to map more compellingly than any other book the promise and risk of the information society. As with everything Sunstein writes, this beautiful and clear book has something to teach the

experts, and lots to teach the rest of us."--Lawrence Lessig, author of Free Culture and The Future of Ideas

"Infotopia is a persuasive and sophisticated meditation on the ways in which the Web is not just living up to its early hype, but transcending it. Cass Sunstein has given us a brilliant integrative view of how the distributed users of the Internet can band together to produce extraordinary

work--along with the circumstances that best give rise to deliberation rather than groupthink."--Jonathan Zittrain, Professor of Internet Governance and Regulation, Oxford University

"Cass Sunstein's new book is a lively illustration of emerging mechanisms for collective rationality never anticipated in the classic writings of Madison, Marx, or Milton (Friedman). Neither a utopian nor a Luddite, Sunstein provides just the right mix of enthusiasm and caution. Ironically, in

arguing for the tremendous potential of the group mind, Sunstein demonstrates a command of law, social science, and computer science rarely found in any individual author--and produces a very fun read."--Robert MacCoun, Professor of Public Policy and Law, University of California at Berkeley

"In our knowledge-based world, extracting useful information from society is more important than ever. Sunstein convincingly reveals the limitations of popular processes like deliberation while showing how collectives--under certain conditions--can effectively solve many problems. An engaging read,

full of eye-opening examples,Infotopia shows how and why our efforts to harness knowledge must evolve."--Michael J. Mauboussin, Chief Investment Strategist, Legg Mason Capital Management and author of More Than You Know: Finding Financial Wisdom in Unconventional Places

As the dire history of planned economies highlights, small well-informed groups of people will often make far worse decisions than large numbers of people, acting independently, would make. In Infotopia, Cass Sunstein looks at the "wisdom of the many"--particularly as seen on today's

Internet--illuminating many new ways of collecting and evaluating information and making effective decisions.

Sunstein shows how the on-line efforts of many people coming together help companies, schools, governments, and individuals to amass ever-growing bodies of accurate knowledge. He describes for instance how Wikipedia, through an endless flurry of self-correcting exchanges, collects information

on everything from politics and business to science fiction. Open-source software--which licenses programmers to use, change, and improve the software--taps the power of large numbers of people to spur technological development. And prediction markets--such as the famous Iowa Electronic Market,

where people bet real money on the outcome of local and national elections--collect information in a way that allows companies, ranging from computer makers to Hollywood studios, to make better decisions about the future. Sunstein reveals why these revolutionary new methods are so astoundingly

accurate and he also shows how people can take advantage of "the wisdom of the many" without succumbing to the dangers of herd mentality.

"Sunstein, one of the biggest of America's internet big thinkers, has written an intriguing new book in which he argues that Hayek's insights about the genius of markets are equally true of the internet."

--Patti Waldmeir, Financial Times

"This extraordinary work synthesizes the latest in how we know, with the latest in what the web has become, to map more compellingly than any other book the promise and risk of the information society."

--Lawrence Lessig, author of Free Culture and The Future of Ideas

"Vivid, readable, and informativea show-me-the-money guide to what soars and what stumbles from the stable of Internet dreams."

--Jedediah Purdy, American Prospect

Sunstein develops a deeply optimistic understanding of the human potential to pool information, and to use that knowledge to improve lives without falling back on prejudices.

Cass R. Sunstein is Karl N. Llewellyn Distinguished Service Professor of Jurisprudence at the University of Chicago Law School, a contributing editor at the New Republic and the American Prospect, and a frequent contributor as well to such publications as the New York Times and the Washington Post.

He is the recipient of the Henderson Prize and the Goldsmith Book Prize; his many books include Radicals in Robes, Republic.com, Why Societies Need Dissent, and Designing Democracy: What Constitutions Do. He lives in Chicago, Illinois.